If people know you are on vacation or maternity leave, for instance, they are more likely to wait for your return to follow up. If you are at a work conference, however, they might still expect you to check your email or provide updates.
It usually isn’t enough to just say you’re out and won’t be responding to messages. You’ve got to give people options for how they can get their issue or request resolved. One of the easiest wins here is to provide alternative contact information. That could mean providing your mobile number while you’re out, or, more commonly, providing the phone number and email of the colleague (or department) that will be covering while you’re away.

55% of B2C content creators say that creating visual content is now the main priority. Here are key ways of how adding visuals enhances your auto reply messages.
I’ve named the conference I was attending a couple of times in my out of office. That particular conference is a big enough deal in my field that some of the people emailing me were probably also in attendance, which made it worth specifying, in addition to setting expectations about email response times and overall availability.